Patent application title: IP NETWORK SERVICE QUALITY MANAGEMENT BY DISTRIBUTED ADMISSION CONTROL BASED ON A SIGNALLING PROTOCOL

Abstract:

Procedure and device for managing the quality of service hop-by-hop in a
packet-based communications network comprising several arteries linked
together by a router, the network supporting a signalling protocol. The
procedure comprises at least at each router a step of reserving the
resources on the arteries gradually and a step ensuring once the
communication has been established that the packets of one and the same
connection follow the path between the sending source and the destination
on which the resources have been reserved.

Claims:

1. A method for managing the quality of service hop-by-hop in a
packet-based communications network comprising several arteries linked
together by a router, the network supporting a signaling protocol,
comprising at each router the following steps:dynamically the
establishment and the releasing of the circuits required either by the
application package level, or by a user,the reservation of resources on
the arteries for each established circuit; with each reservation is
associated the bandwidth, the precedence of the reservation, and the
service class which encompasses this resource,the preemption of a
communication, if there are not sufficient resources available for a new
communication having a higher priority level.

2. The method as claimed in claim 1, wherein the resource reservations are
performed during the propagation of the network core signaling.

3. The method as claimed in claim 2, wherein the routing is based:either
on the trunking table present in the routersor on an application package
level routing protocol.

4. The method as claimed in claim 1, wherein it uses an IP network.

5. A device for managing the quality of service hop-by-hop in a
communications network comprising several arteries linked together by
means of a router, and a signaling protocol, wherein each router or node
of the network comprises a means suitable for:establishing and releasing
in a dynamic manner the circuits required either by the application
package level, or by a user;routing the communications according to
trunking tables,reserving the resources on the arteries for each
established circuit; and associating with each reservation the bandwidth,
the precedence of the reservation, and the service class which
encompasses this resource,managing the preemption of a communication if
there are not sufficient resources available for a new communication
having a higher priority level.

6. The device as claimed in claim 5, wherein the network is a meshed
network based on the IP protocol.

7. A component for managing the quality of service within a communications
network comprising several arteries according to a method of claim 1,
comprising at least the following elements:an interface for configuring
the system,an interface for managing the arteries,a resources manager,a
stack of signaling protocols,an interface with the user signaling,an
interface with the network signaling,an integrated routing protocol,a
module for controlling the resources manager.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001]The present Application is based on International Application No.
PCT/EP2005/054075, filed on Aug. 18, 2005, which in turn corresponds to
French Application No. 0409027, filed on Aug. 20, 2004, and priority is
hereby claimed under 35 USC §119 based on these applications. Each
of these applications are hereby incorporated by reference in their
entirety into the present application.

FIELD OF THE INVENTION

[0002]The invention relates to a procedure and a device making it possible
to manage service quality hop-by-hop within a communications network
comprising several arteries linked together by a routing device for
example.

BACKGROUND OF THE INVENTION

[0003]The invention applies in respect of multimedia stream transport on a
meshed network based on the IP protocol (Internet Protocol).

SUMMARY OF THE INVENTION

[0004]In certain telecommunication networks, the management of service
quality at a global level, differentiated or Diffserv services, is not
sufficient. It turns out also to be necessary to dynamically manage
connection-oriented streams each having specific quality of service (QoS)
parameters such as precedence, latency time, jitter, loss sensitivity,
bandwidth.

[0005]For each of these streams, it is necessary to manage: [0006]The
admission control for connections with a signaling protocol, [0007]The
routing of the streams in a meshed network according to the availability
of the resources in the network, [0008]The control of the sending of the
user data in accordance with the reservations previously performed.

[0009]Stream-based management of quality of service is based mainly on the
mechanisms for reserving resources which take account of the quality of
service or QoS parameters. The reservation of the resources is based on
signaling protocols (H.323 or SIP).

DiffServ offers three classes of service: [0010]The service class
corresponding to the maximum priority which makes it possible to minimize
the delay and its variation for real-time traffic or Expedited Forwarding
(EF) is assumed to be used for multimedia and video services requiring
real-time capabilities (latency time, jitter). [0011]The service class
which allows the transmission of the data without taking account of the
latencies or of the variations in delay or Assured Forwarding (AF) is
assumed to be used for the data services which demand bandwidth
guarantees (bandwidth, low losses). [0012]The low priority or Best Effort
(BE) service class which is used for the services not having any
bandwidth, latency time or jitter constraint.

[0013]The DiffServ model has not standardized any signaling protocol, to
avoid the storage of contexts in the routers. This model has been
developed by the IETF to solve the switchover to Internet scale. The
DiffServ model has been specified for telecommunications network
operators. This model requires a scheduling of the network corresponding
to the level of service required by the users connected to the network.
This model operates correctly if the core of the network has sufficient
resources and if these resources are correctly scheduled. Generally, the
network resources are explicitly reserved by the operator for the network
established for its client. In the case of applications having global
mobility constraints and/or constraints of resources present in the core
of the network that are below the global requirements, the scheduling of
resources is no longer possible.

[0014]For these cases, it turns out useful: [0015]to reserve resources
forming part of a Service class for the time of a communication. This
reservation is performed with a signaling protocol. [0016]to supply these
resources to the system when the communication is terminated, typical
case is speech communication.

[0017]The procedure according to the invention relies notably on the
following principles: [0018]the reservation of resources is managed by
a connections admission control mechanism, which controls the
establishment of the streams according to: the type of communication, the
resources available and also the precedence of the communication.
[0019]because of the frequent changes of topology of the network, the
connections admission control (CAC) is present in each node of the
network and therefore is distributed over the network. The CAC function,
as in a connection-oriented network, reserves the resources gradually
during the establishment of the connection. These resources are reserved
on the communication support arteries. [0020]a specific routing protocol
can be developed to take account of the evolution of the reservation of
resources on the arteries of the network core (QoS routing, flooding
route search, etc.). [0021]once the communication has been established
the procedure ensures that all the packets of one and the same connection
follow the route on which the resources have been reserved for this
communication.

[0022]The invention relates to a procedure for managing the quality of
service hop-by-hop in a packet-based communications network comprising
several arteries linked together by a router, the network supporting a
signaling protocol, characterized in that it comprises at least at each
router a step of reserving the resources on the arteries hop-by-hop and a
step ensuring once the communication has been established that the
packets of one and the same connection follow the path between the
sending source and the destination on which the resources have been
reserved.

[0023]The resource reservations are for example performed during the
propagation of the network core signaling.

[0024]The procedure can comprise the following steps: [0025]Establish
and release, dynamically, circuits required either by the application
package level, or by a user, [0026]Reserve the resources on the arteries
for each established circuit; with each reservation is associated the
bandwidth, the precedence of the reservation, and the service class which
encompasses this resource, [0027]Ensure the preemption of a
communication, if there are not sufficient resources available for a new
communication having a higher priority level.The routing is for example
based: [0028]either on the trunking table present in the routers [0029]or
on an application package level routing protocol.

[0030]The procedure for example uses an IP network.

[0031]The invention also relates to a device for managing the quality of
service hop-by-hop in a communications network comprising several
arteries linked together by means of a router, and a signaling protocol,
characterized in that each router or node of the network comprises a
means suitable for reserving the resources gradually and a means suitable
for guaranteeing that the packets of one and the same communication
follow the same route on which the signaling protocol has previously
reserved the resources for the communication.

[0032]The device for example comprises means suitable for:
[0033]establishing and releasing in a dynamic manner the circuits
required either by the application package level, or by a user,
[0034]routing the communications according to trunking tables (present in
the router or formulated by a routing protocol taking account of the
reservations performed), [0035]reserving the resources on the arteries
for each established circuit; and associating with each reservation the
bandwidth, the precedence of the reservation, and the service class which
encompasses this resource, [0036]managing the preemption of a
communication if there are not sufficient resources available for a new
communication having a higher priority level.

[0037]The network is for example a meshed network based on the IP
protocol.

[0038]The invention also relates to a component for managing the quality
of service within a communications network comprising several arteries,
comprising at least the following elements: [0039]an interface for
configuring the system, [0040]an interface for managing the arteries,
[0041]a resources manager, [0042]a stack of signaling protocols, [0043]an
integrated routing protocol, [0044]a module for controlling the resources
manager.

[0045]The invention has in particular the following advantages:

[0046]It makes it possible in particular to control the state of the
resource reservations of an artery on a telecommunications network before
propagating the call which is the subject of a multimedia communication,
for example. The control being carried out at each hop at the level of
each artery of a meshed network, the quality of service of the multimedia
communication can, in this way, be guaranteed end-to-end.

[0047]The type of organization according to the invention offers the
advantage of operating when the bandwidth available on the arteries of
the network is low, since it allows the implementation of connections
admission control mechanisms on the arteries of the communications
network.

[0048]The organization also makes it possible to ensure that the packets
of one and the same communication all follow the same route on which the
signaling protocol has previously reserved the resources for the
communication, while the IP routing can designate other optimal routes.

[0049]The system which is the subject of the present invention also allows
the reservation of network resources for the OODA (or Observe Orient
Decide and Act) loops of NCW (Network Centric Warfare) applications.

[0050]Still other objects and advantages of the present invention will
become readily apparent to those skilled in the art from the following
detailed description, wherein the preferred embodiments of the invention
are shown and described, simply by way of illustration of the best mode
contemplated of carrying out the invention. As will be realized, the
invention is capable of other and different embodiments, and its several
details are capable of modifications in various obvious aspects, all
without departing from the invention. Accordingly, the drawings and
description thereof are to be regarded as illustrative in nature, and not
as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

[0051]The present invention is illustrated by way of example, and not by
limitation, in the figures of the accompanying drawings, wherein elements
having the same reference numeral designations represent like elements
throughout and wherein:

[0052]FIG. 1 a functional chart of the procedure according to the
invention,

[0053]FIG. 2 a general chart presenting the various issues dealt with by
the procedure according to the invention,

[0054]FIG. 3 an exemplary architecture of a communications network using
the procedure.

DETAILED DESCRIPTION OF THE INVENTION

[0055]In order to better elucidate the invention, the description which
follows given by way of wholly nonlimiting illustration relates to a
telecommunications network using the Diffserv model combined with a
signaling protocol making it possible to control the network resources.

[0056]Hop-by-hop routing can be likened to the creation of a circuit
network in parallel or overlay on a datagram network core. The overlay
circuit operates on a set of private links installed in a shared operator
infrastructure, for example.

[0057]The circuits are established dynamically with a signaling protocol,
such as H.323 or SIP developed by international bodies. The circuit
establishment request is made by the user who requires an application
package circuit for a given stream (example: speech stream,
videoconferencing, etc.). The establishment of the circuit is managed by
a local server LCC (Local Call Control, H.323 Gatekeeper, SIP server).

[0058]The network core signaling is also based on the ITU or IETF
standards (H.323, SIP). This signaling propagates in the network core the
requirement of the user or of the application. The resource reservations
are performed gradually during this propagation.

[0059]FIG. 1 shows diagrammatically a functional chart of a component for
managing the quality of service according to the invention. It comprises
for example: [0060]An interface for configuring the system or ACS 1;
[0061]An interface for managing the arteries 2; [0062]An interface for
controlling the router 3; [0063]A resources manager or CAC having in
particular as functions: the connection, the admission, the allocation of
the resources with the passage of time, and the management of the
preemptions of the communications 4; [0064]A stack of signaling protocols
5; [0065]An interface with the user signaling (LCC) 6; [0066]An interface
with the network signaling (QSM) 7; [0067]An integrated routing protocol
8; [0068]A general control module for the QSM resources manager 9.

[0069]The general control module 9 is in particular charged with the
distribution of the artery level information (state, topology, bandwidth,
etc.) to the internal QSM modules (routing, CAC management). This module
is also charged with the reconfiguration of the queues of the router, if
the bandwidth available on the link changes.

[0070]The CAC module 4 stores the resources reservation performed during
the establishment of the circuits. For each reservation, this module
stores the bandwidth reservation, the precedence and also the service
class (EF, AF1, AF2). These parameters are used to perform the admission
control for the new connections.

[0071]The CAC module formulates a calculation of average latency for the
communication. If this latency exceeds an admissible maximum for the
communication, the admission control rejects the communication (for
example, in the case where there are more than 2 satellite hops for a
telephone call). The latency of the communication is the sum of all the
latencies of the communication (compression, latencies of the arteries,
buffering).

[0072]The routing and discovery module 8 might not be present according to
the protocols used. In this case, the QSM module reads the routing table
to obtain the route or routes to the destination server (LCC) and
propagates the connection request on this route.

[0073]The signaling stack 5 takes into account the access protocol managed
by the LCC and manages the signaling protocols propagated on the network.
These protocols comply with the standards established by the ITU and the
IETF. Complementary information, necessary for the establishment of the
communication, is transported in a user to user information element
(UUIE), for example, the destination server address, the precedence of
the communication, the average latency on the route, etc.

[0074]Functionally, the procedure according to the invention operates in
the following manner. The procedure ensures: [0075]Dynamically the
establishment and the releasing of the circuits required either by the
application package level, or by a user (telephony, for example);
[0076]The reservation of resources on the arteries for each established
circuit; with each reservation is associated the bandwidth, the
precedence of the reservation, and the service class which encompasses
this resource, [0077]The preemption of a communication, if there are not
sufficient resources available for a new communication having a higher
priority level, [0078]The routes making it possible to reach the
destination LCC server in charge of the communication; the routing can be
based: [0079]Either on the trunking table present in the routers, in
this case, the establishment is dispatched to the destination server
(LCC) according to the optimal route formulated by the router's routing
protocol, in the event of equivalent routes, it is possible to explore
alternative routes, [0080]Or on an application package level routing
protocol (QoS routing, flooding route search, etc.) [0081]The
successive packets of one and the same stream are trunked on the same
arteries, even when the topology of the network changes.

[0082]FIG. 2 shows diagrammatically a chart comprising in its upper part,
the actions managed conventionally by a router according to the prior art
and in its lower part the various issues dealt with by the procedure
according to the invention designated QSM.

[0083]FIG. 3 represents an exemplary implementation of the procedure
within a network comprising several QSM routers according to the
invention. The routers are linked by arteries. A router is connected to
an LCC destination server.

[0084]It will be readily seen by one of ordinary skill in the art that the
present invention fulfils all of the objects set forth above. After
reading the foregoing specification, one of ordinary skill in the art
will be able to affect various changes, substitutions of equivalents and
various aspects of the invention as broadly disclosed herein. It is
therefore intended that the protection granted hereon be limited only by
definition contained in the appended claims and equivalents thereof.